Methods and Apparatuses for Use in a Mobile Communication Network

ABSTRACT

The proposed technology relates to the issue of supporting release of common radio resources in a radio communication network. A radio network controller sends an indication of a value of a timer for implicit release of common radio resources to a base station. The base station receives the indication of a value of a timer for implicit release of common radio resources and determines whether to release common radio resources based on the indication of a value of the timer for implicit release of common radio resources. In this way, by using the indication of a value of the timer for implicit release the base station will be able to correctly determine whether to release the common resources upon reception of a report of empty buffer status from a UE. This will eliminate misinterpretations of the empty buffer status report, and avoid unnecessary radio link failures.

RELATED APPLICATIONS

This application is a continuation of co-pending U.S. patent applicationSer. No. 13/995,683, filed 19 Jun. 2013, which is a national stage entryunder 35 U.S.C. §371 of international patent application serial no.PCT/SE2013/050362, filed 2 Apr. 2013, which claims priority to and thebenefit of U.S. provisional patent application Ser. No. 61/682,442,filed 13 Aug. 2012. The entire contents of each of the aforementionedapplications is incorporated herein by reference.

TECHNICAL FIELD

The technology relates to radio communications and efficient use ofradio resources.

BACKGROUND

The technology in this application is described in a non-limitingexample UMTS Terrestrial Radio Access Network, UTRAN/Wideband CodeDivision Multiple Access, WCDMA, network that supports High Speed PacketAccess, HSPA. A basic example of an UTRAN/HSPA type of system isillustrated in FIG. 1. This example network basically comprises a numberof base stations, also called Node Bs 100-1, 100-2; 4, 6, and one ormore Radio Network Controllers, RNCs, 200-1, 200-2; 8. A RNC providescontrol functionality for one or more Node Bs. The RNC 200-1; 8 alsocommunicates with one or more core network nodes in the Core Network,CN, 400, which may be connected to one or more other networks, e.g., theInternet, public and private telephone networks, etc. The RNC and itscorresponding Node Bs are often denoted the Radio Network Subsystem,which provides the basic radio access for one or more User Equipments,UEs 300; 14. There are a number of interfaces in the network. The Uuinterface connects the Node B and the UE. The Iub interface connects theRNC and the Node B. The Iur interface connects two RNCs to each other.The IuCS and IuPS interfaces connect the RNC and the CN.

This type of network normally supports a connection state for a UE inwhich dedicated radio resources are allocated to the UE forcommunication with the network, and another connection state in whichcommon radio resources such as common Enhanced Dedicated Channel, E-DCH,resources are available to the UE.

The common resources may be released in several ways, for exampleexplicitly by the network or implicitly by the UE. In the latter case,the UE basically maintains the common radio resources until it hasemptied its transmit buffer, possibly waiting for an inactivity timer toexpire, and then releases the common radio resources. The UE typicallyreleases the resources after scheduling information with a report ofempty buffer status has been transmitted to the network, and after thelast retransmission process has been acknowledged or the maximum numberof retransmissions has been reached. The reception of the schedulinginformation with the empty buffer status report from the UE willnormally be interpreted by the network as an implicit release by the UE,and the network then also releases the resources on the network side.

The inactivity timer, which is also referred to as a timer for implicitrelease of common resources or simply an implicit release timer, iscontrolled by the RNC and broadcasted to the relevant UE(s) in thesystem information. The inactivity timer is normally used because the UEmay have new data to transmit just a few ms after the completion of thelast transmission. The selected value of the timer is related to thetrade-off between releasing the resources as quickly as possible inorder to be able to assign the resources to another user and the risk ofreceiving a request from the same user immediately after releasing theresources.

However, if the inactivity timer in the UE is enabled, it has been notedthat there may be situations when the network incorrectly releases thecommon resources, resulting in radio link failures and data losses.

There is thus a need for a more robust solution for release of commonresources in radio communication networks.

SUMMARY

The proposed technology overcomes these and other drawbacks of the priorart.

It is a general object to provide support for correct release of commonradio resources in a radio communication network.

This and other objects are met by the proposed technology as defined bythe appended patent claims.

According to a first aspect, there is provided a method performed by abase station for supporting release of common radio resources in a radiocommunication network. The base station receives an indication of avalue of a timer for implicit release of common radio resources from aradio network controller, and the base station determines whether torelease common radio resources based on the indication of a value of thetimer for implicit release of common radio resources.

According to a second aspect there is provided a method performed by aradio network controller for supporting release of common radioresources in a radio communication network. The radio network controllersends an indication of a value of a timer for implicit release of commonradio resources to a base station to enable the base station todetermine whether to release common radio resources based on theindication of a value of the timer for implicit release of common radioresources.

According to a third aspect, there is provided a base station for aradio communication network. The base station comprises an interfaceconfigured to receive an indication of a value of a timer for implicitrelease of common radio resources from a radio network controller. Thebase station also comprises a processing module configured to determinewhether to release common radio resources based on the indication of avalue of the timer for implicit release of common radio resources.

According to a fourth aspect, there is provided a radio networkcontroller for a radio communication network. The radio networkcontroller comprises an interface configured to send an indication of avalue of a timer for implicit release of common radio resources to abase station to enable the base station to determine whether to releasecommon radio resources based on the indication of a value of the timerfor implicit release of common radio resources.

According to a fifth aspect, there is provided a method for supportingrelease of common Enhanced Dedicated Channel, E-DCH, resources in aradio communication network, wherein a base station is receiving aPHYSICAL SHARED CHANNEL RECONFIGURATION REQUEST message from a radionetwork controller including a ‘Common E-DCH Implicit Release Timer’information element, IE, that indicates whether a ‘E-DCH transmissioncontinuation back off’ period is set to zero or to a value differentfrom zero.

According to a sixth aspect, there is provided a base station for aradio communication network, wherein the base station is configured forreceiving a PHYSICAL SHARED CHANNEL RECONFIGURATION REQUEST message froma radio network controller including a ‘Common E-DCH Implicit ReleaseTimer’ information element, IE, that indicates whether a ‘E-DCHtransmission continuation back off’ period is set to zero or to a valuedifferent from zero.

According to a seventh aspect, there is provided a method for supportingrelease of common Enhanced Dedicated Channel, E-DCH, resources in aradio communication network, wherein a radio network controller issending a PHYSICAL SHARED CHANNEL RECONFIGURATION REQUEST message to abase station including a ‘Common E-DCH Implicit Release Timer’information element to indicate whether a ‘E-DCH transmissioncontinuation back off’ period is set to zero or to a value differentfrom zero.

According to an eighth aspect, there is provided a radio networkcontroller for a radio communication network, wherein the radio networkcontroller is configured for sending a PHYSICAL SHARED CHANNELRECONFIGURATION REQUEST message to a base station including a ‘CommonE-DCH Implicit Release Timer’ information element to indicate whether a‘E-DCH transmission continuation back off’ period is set to zero or to avalue different from zero.

In this way, by using the indication of a value of the timer forimplicit release the base station will be able to correctly determinewhether to release the common resources upon reception of a report ofempty buffer status from a UE. This will eliminate misinterpretations ofthe empty buffer status report, and avoid unnecessary radio linkfailures.

Other advantages will be appreciated when reading the detaileddescription.

BRIEF DESCRIPTION OF THE DRAWINGS

The proposed technology, together with further objects and advantagesthereof, may best be understood by making reference to the followingdescription taken together with the accompanying drawings, in which:

FIG. 1 is a schematic diagram illustrating an example of a UTRAN/HSPAtype communication network.

FIG. 2 is a schematic flow diagram illustrating an example of a methodperformed by a base station for supporting release of common radioresources in a radio communication network according to an embodiment.

FIG. 3 is a schematic flow diagram illustrating a particular example ofthe determining step of FIG. 2 according to an embodiment.

FIG. 4 is a schematic flow diagram illustrating another particularexample of a method for supporting release of common radio resourcesaccording to an embodiment.

FIG. 5 is a schematic flow diagram illustrating an example of a methodperformed by a radio network controller for supporting release of commonradio resources in a radio communication network according to anembodiment.

FIG. 6 is a schematic flow diagram illustrating an example of a methodperformed by a radio network controller for supporting release of commonradio resources in a radio communication network according to anotherembodiment

FIG. 7 is a schematic flow diagram illustrating another example of amethod performed by a radio network controller for supporting release ofcommon radio resources in a radio communication network according to anembodiment.

FIG. 8 is a schematic block diagram illustrating an example of a basestation and a radio network controller for a radio communication networkand the corresponding RNC-BS interface according to an embodiment.

FIG. 9 is a schematic block diagram illustrating a particular example ofa base station and a radio network controller and the correspondingRNC-BS interface according to an embodiment, including also anillustration of the UE-BS interface between the base station and a UE.

FIG. 10 is a schematic flow diagram illustrating yet another particularexample of a method for supporting release of common radio resources.

FIG. 11 is a schematic block diagram illustrating an example of a userequipment according to an embodiment.

FIG. 12 is a schematic block diagram illustrating an example of a basestation, such as a Node B, according to an embodiment.

FIG. 13 is a schematic block diagram illustrating an example of a radionetwork controller according to an embodiment.

DETAILED DESCRIPTION

Throughout the drawings, the same reference numbers are used for similaror corresponding elements.

The present technology relates to the scenario when common radioresources such as common Enhanced Dedicated Channel, E-DCH, resourcesare available to the UE. The common resources may be released in severalways, for example explicitly by the network or implicitly by the UE. Inthe latter case, the UE basically maintains the common radio resourcesuntil it has emptied its transmit buffer, possibly waiting for aninactivity timer to expire, and then releases the common radioresources.

As previously mentioned, if the inactivity timer in the UE is notenabled, the procedure for implicit release works fine. However, if theinactivity timer in the UE is enabled, it has been noted that there maybe situations when the network incorrectly releases the commonresources, resulting in radio link failures and data losses.

The inventors have realized that this has to do with the fact that ifenough space is available at the end of a packet data unit, the UE mayattach scheduling information with an empty buffer status indicationregardless of whether the inactivity timer has expired. Such an emptybuffer status indication may then be misinterpreted by the network as animplicit release by the UE, although the inactivity timer has not yetexpired. If the network incorrectly releases the resources, the UE willdetect a radio link failure if the UE wants to resume transmissionbefore the inactivity timer has expired, and data will be lost.

FIG. 2 is a schematic flow diagram illustrating an example of a methodperformed by a base station, BS, for supporting release of common radioresources in a radio communication network according to an embodiment.In step S1, the base station receives an indication of a value of atimer for implicit release of common radio resources from a radionetwork controller. In step S2, the base station determines whether torelease common radio resources based on the indication of a value of thetimer for implicit release of common radio resources.

By using the indication of a value of the timer for implicit release thebase station will be able to correctly determine whether to release thecommon resources upon reception of a report of empty buffer status froma UE. This will eliminate misinterpretations of the empty buffer statusreport, and avoid unnecessary radio link failures.

Step S2 is sometimes referred to as a ‘common resource release decision’in the relevant 3GPP standards.

In a particular embodiment, the common radio resources are commonEnhanced Dedicated Channel, E-DCH, resources, and the indication of avalue of the timer for implicit release is an indication of a value of atimer for implicit release of common E-DCH resources.

The indication of a value of the timer for implicit release of commonE-DCH resources may for example indicate whether a ‘E-DCH transmissioncontinuation back off’ period is set to zero or to a value differentfrom zero.

As previously implied, the step S2 of the base station determiningwhether to release common radio resources may be performed uponreception of a report of empty buffer status from a User Equipment, UE.

In particular, the report of empty buffer status may be received aspiggybacked Scheduling Information, SI, with a Total E-DCH BufferStatus, TEBS, value equal to zero, as will be explained in detail lateron.

In a particular example embodiment, as illustrated in FIG. 3, when thecommon radio resources are common Enhanced Dedicated Channel, E-DCH,resources, and the indication of a value of a timer for implicit releaseof common radio resources is an indication of a value of a timer forimplicit release of common E-DCH resources, the step S2 of the basestation determining whether to release common resources includes thestep S2-1 of the base station determining, based on the indication of avalue of the timer for implicit release of common E-DCH resources,whether the report of empty buffer status from a User Equipment, UE, isdue to an implicit release of common E-DCH resources by the UE.

By way of example, the method may include the step where the basestation releases the common E-DCH resources if the indication of a valueof the timer for implicit release of common E-DCH resources is equal tozero.

On the other hand, the method may include the step where the basestation does not release the common E-DCH resources if said indicationof a value of said timer for implicit release of common E-DCH resourcesis different from zero. In other words, the base station maintains thecommon E-DCH resources in this case. For additional details, referencecan be made to FIG. 10.

In this example, it is thus sufficient to indicate whether the timer forimplicit release is zero or not. However, the indication of a value ofthe timer for implicit release may alternatively indicate the exactvalue of the timer such as the exact value of the ‘E-DCH transmissioncontinuation back off’ period. Other examples will be described lateron.

As will be explained in detail later on, the indication of a value ofthe timer for implicit release of common radio resources may for examplebe received in a PHYSICAL SHARED CHANNEL RECONFIGURATION REQUESTmessage.

The PHYSICAL SHARED CHANNEL RECONFIGURATION REQUEST message is part ofthe signaling over the so-called Iub interface between RNC and Node B.

The indication of a value of the timer for implicit release of commonradio resources may be included in a new ‘Common E-DCH Implicit ReleaseTimer’ information element in the PHYSICAL SHARED CHANNELRECONFIGURATION REQUEST message.

As an example, the indication of a value of the timer for implicitrelease of common radio resources in the ‘Common E-DCH Implicit ReleaseTimer’ information element is defined to be of ENUMERATED type withvalues zero or more than zero.

Embodiments of the present technology will now be described from theperspective of the radio network controller.

FIG. 5 is a schematic flow diagram illustrating an example of a methodperformed by a radio network controller for supporting release of commonradio resources in a radio communication network according to anembodiment. In step S11, the radio network controller sends anindication of a value of a timer for implicit release of common radioresources to a base station to enable the base station to determinewhether to release common radio resources based on the indication of avalue of the timer for implicit release of common radio resources.

In a particular embodiment, the common radio resources are commonEnhanced Dedicated Channel, E-DCH, resources, and the indication is anindication of a value of a timer for implicit release of common E-DCHresources.

By way of example, the indication of a value of the timer for implicitrelease of common E-DCH resources may indicate whether a ‘E-DCHtransmission continuation back off’ period is set to zero or to a valuedifferent from zero.

In a particular example embodiment, the radio network controller sendsthe indication of a value of said timer for implicit release of commonE-DCH resources to the base station to enable the base station todetermine, based on the indication of a value of the timer for implicitrelease of common E-DCH resources, whether to release common E-DCHresources upon reception of a report of empty buffer status from a UserEquipment, UE.

More specifically, the radio network controller sends the indication ofa value of the timer for implicit release of common E-DCH resources tothe base station to enable the base station to determine, based on theindication of a value of the timer for implicit release of common E-DCHresources, whether to release common E-DCH resources upon reception ofpiggybacked Scheduling Information, SI, with a Total E-DCH BufferStatus, TEBS, value equal to zero from a User Equipment, UE.

For example, the radio network controller sends the indication of avalue of said timer for implicit release of common E-DCH resources tothe base station to enable the base station to release, upon receptionof the report of empty buffer status from the UE, the common E-DCHresources if the indication of a value of the timer for implicit releaseof common E-DCH resources is equal to zero. Complementary, the basestation is enabled to not release, i.e. maintain, the common E-DCHresources if the indication of a value of the timer for implicit releaseof common E-DCH resources is different from zero.

The radio network controller may for example send the indication of avalue of a timer for implicit release of common radio resources to thebase station in a PHYSICAL SHARED CHANNEL RECONFIGURATION REQUESTmessage.

The indication of a value of said timer for implicit release of commonradio resources may then be included in a ‘Common E-DCH Implicit ReleaseTimer’ information element in the PHYSICAL SHARED CHANNELRECONFIGURATION REQUEST message.

In a particular example, schematically illustrated in the flow diagramof FIG. 6, the method comprises the optional step (S10) of the radionetwork controller adding an information element including theindication of a value of a timer for implicit release of common radioresources in a message. The step (S11) of the radio network controllersending an indication of a value of a timer for implicit release ofcommon radio resources then comprises the step (S11-1) of the radionetwork controller sending the message with the added informationelement including the indication of a value of a timer for implicitrelease of common radio resources to the base station. For example, theradio network controller initially provides the value of the timer forimplicit release, adds the new information element including theindication of the timer value in the message and finally sends themessage to the base station.

By way of example, the indication of a value of said timer for implicitrelease of common radio resources in the ‘Common E-DCH Implicit ReleaseTimer’ information element is defined to be of ENUMERATED type withvalues zero or more than zero.

FIG. 8 is a schematic block diagram illustrating an example of a basestation, BS, and a radio network controller, RNC, for a radiocommunication network and the corresponding RNC-BS interface accordingto an embodiment.

The base station 100 comprises an interface 110 configured to receive anindication of a value of a timer for implicit release of common radioresources from the radio network controller 200. The base stationfurther comprises a processing module 120 configured to determinewhether to release common radio resources based on the indication of avalue of the timer for implicit release of common radio resources.

The radio network controller 200 comprises an interface 210 configuredto send an indication of a value of a timer for implicit release ofcommon radio resources to a base station to enable the base station todetermine whether to release common radio resources based on theindication of a value of the timer for implicit release of common radioresources.

The RNC-BS interface thus includes a novel indication of a value of atimer for implicit release of common radio resources.

FIG. 9 is a schematic block diagram illustrating a particular example ofa base station and a radio network controller and the correspondingRNC-BS interface according to an embodiment, including also anillustration of the UE-BS interface between the base station and a UE.

Preferably, the interface 110 is configured to receive an indication ofa value of a timer for implicit release of common Enhanced DedicatedChannel, E-DCH, resources, and the processing module 120 is configuredto determine whether to release common E-DCH resources.

In this connection, the interface 110 may be configured to receive theindication of a value of the timer for implicit release of common E-DCHresources in the form of an indication of whether a value of a ‘E-DCHtransmission continuation back off’ period is set to zero or to a valuedifferent from zero.

Typically, the processing module 120 is configured to determine, basedon the indication of a value of the timer for implicit release of commonradio resources whether to release common radio resources upon receptionof a report of empty buffer status from a User Equipment, UE.

In particular, the base station 100 may also include a transceivermodule 130 configured to receive the report of empty buffer status aspiggybacked Scheduling Information, SI, with a Total E-DCH BufferStatus, TEBS, value equal to zero.

By way of example, the processing module 120 may be configured torelease the common E-DCH resources if the indication of a value of saidtimer for implicit release of common E-DCH resources is equal to zero.

On the other hand, the processing module 120 may be configured tomaintain the common E-DCH resources if the indication of a value of thetimer for implicit release of common E-DCH resources is different fromzero. In other words, the common E-DCH resources are not released inthis case, at least not as long as the timer for implicit release isdifferent from zero.

In a particular example embodiment, the interface 110 is configured toreceive the indication of a value of the timer for implicit release ofcommon radio resources in a ‘Common E-DCH Implicit Release Timer’information element in a PHYSICAL SHARED CHANNEL RECONFIGURATION REQUESTmessage.

It should be understood that the ‘Common E-DCH Implicit Release Timer’information element, IE, is a new IE added to the ‘Common E-DCH SystemInformation’ information element of the PHYSICAL SHARED CHANNELRECONFIGURATION REQUEST message.

The PHYSICAL SHARED CHANNEL RECONFIGURATION REQUEST message is part ofthe signaling over the so-called Iub interface between RNC and Node B.

From the RNC perspective once again, the interface 210 of the RNC 200 ispreferably configured to send an indication of a value of a timer forimplicit release of common Enhanced Dedicated Channel, E-DCH, resourcesto enable the base station to determine whether to release common E-DCHresources.

The interface 210 may for example be configured to send the indicationof a value of the timer for implicit release of common E-DCH resourcesin the form of an indication of whether a value of a ‘E-DCH transmissioncontinuation back off’ period is set to zero or to a value differentfrom zero.

In a particular example, the radio network controller 200 furthercomprises an optional processing module 220 configured to add aninformation element including the indication of a value of the timer forimplicit release of common radio resources in a message. The interface210 is then configured to send the message to the base station.

By way of example, the radio network controller 200 further comprises aprocessing module 220 configured to include the indication of a value ofthe timer for implicit release of common radio resources in a ‘CommonE-DCH Implicit Release Timer’ information element in a PHYSICAL SHAREDCHANNEL RECONFIGURATION REQUEST message. The interface 210 is thenconfigured to send the PHYSICAL SHARED CHANNEL RECONFIGURATION REQUESTmessage to the base station 100.

The RNC-BS interface may for example be the Iub interface, and the UE-BSinterface may be the Uu interface.

For a better understanding of the proposed technology, a brief overviewand analysis of a particular type of example network will now bedescribed. The proposed technology is not limited thereto.

By way of example, a WCDMA/HSPA network supports a CELL Forward AccessChannel, CELL_FACH, state and a CELL Dedicated Channel, CELL_DCH, state.CELL_FACH state is a connection state (or mode) for a UE in which onlycommon radio resources are available to the UE for communication withthe network, i.e., no dedicated radio resources are allocated to the UE.The CELL_DCH state is a connection state (or mode) for a UE in whichdedicated radio resources have been allocated to the UE.

For Frequency Division Duplexing, FDD, the E-DCH transmission inCELL_FACH state and Idle Mode is a mechanism to improve the performanceof the random access procedure. The Enhanced Uplink in CELL_FACH stateand Idle mode combines the Release-99 random access power ramping phasewith E-DCH transmission on common E-DCH resources. The network canconfigure up to 32 common E-DCH resources in one cell. The configurationinformation is broadcast by system information (see 5/5bis).

The E-DCH random access procedure includes the following steps:

-   -   1— Access Request preamble transmissions with preamble power        ramping as in Rel-99;    -   2— Acquisition Indication and assignment of a common E-DCH        resource;    -   3— Data transmission over the assigned E-DCH channel, which is        used to carry either a Common Control Channel, CCCH,        transmission or Dedicated Traffic Channel/Dedicated Control        Channel, DTCH/DCCH, transmission    -   4— Release of the common E-DCH Resource.

For dedicated channels, like DCCH/DTCH, common E-DCH resources can bereleased in the following ways:

-   -   1—Explicitly by the Node B sending a release command on the        E-DCH Absolute Grant Channel, E-AGCH, during the collision        resolved phase.    -   2—If configured by the network, implicitly by the UE. The UE        releases the resources after an empty buffer status has been        reported in the SI to the Node B, and after the last HARQ        process has been acknowledged or maximum number of        retransmission has been reached.    -   3—If contention resolution fails, i.e., no absolute grant is        received by the UE.    -   4—During state transition from CELL_FACH to CELL_DCH.    -   5—Upon a radio link failure.

Regarding the implicit release, 3GPP TS 25.321 [1], section 11.2.2A,incorporated herein by reference, specifies the following:

-   -   Implicit release with E-DCH transmission continuation backoff    -   Implicit resource release is enabled only if “E-DCH transmission        continuation back off” is not set to “infinity”.    -   If implicit resource release is enabled, then in case of        DTCH/DCCH transmission, the timer Tb is set to “E-DCH        transmission continuation back off” value, when TEBS is 0 byte        and the last generated MAC-i PDU with higher layer data is        provided with the PHY-data-REQ primitive to the physical layer        for transmission.    -   If TEBS < > 0 byte is detected while timer Tb is running, then        the timer is stopped and uplink data transmission on the common        E-DCH resource continues.    -   If a MAC-ehs PDU is received while timer Tb is running, then the        tinter is re-started.    -   If the “E-DCH transmission continuation back off” value is set        to “0” or if timer Tb expires the MAC-STATUS-Ind primitive        indicates to RLC for each logical channel that no PDUs shall be        transferred to MAC. TEBS=0 byte is reported to the Node B MAC as        SI in a MAC-i PDU. If the “E-DCH transmission continuation back        off” value is set to “0”, then the SI shall be transmitted with        the MAC-i PDU carrying the last DCCH/DTCH data, given the        serving grant is sufficient to carry the SI in the same MAC-i        PDU together with the remaining DCCH/DTCH data. Otherwise, the        empty buffer status report is transmitted separately with the        next MAC-i PDU.    -   CMAC-STATUS-Ind which informs the RRC about the Enhanced Uplink        in CELL_FACH state and Idle mode process termination is        triggered when the empty buffer status has been reported and no        MAC-i PDU is left in any HARQ process for (re)transmission.

3GPP TS 25.321 [1], section 9.2.5.3.2, incorporated herein by reference,defines for FDD the Total E-DCH Buffer Status as follows

-   -   Total E-DCH Buffer Status (TEBS):    -   The TEBS field identifies the total amount of data available        across all logical channels for which reporting has been        requested by the RRC and indicates the amount of data in number        of bytes that is available for transmission and retransmission        in RLC layer. If MAC-i/is is configured, it also includes the        amount of data that is available for transmission in the        MAC-i/is segmentation entity. When MAC is connected to an AM RLC        entity, control PDUs to be transmitted and RLC PDUs outside the        RLC Tx window shall also be included in the TEBS. RLC PDUs that        have been transmitted but not negatively acknowledged by the        peer entity shall not be included in the TEBS.

Section 11.8.1.6 “Scheduling Information reporting” of [1] specifies howthe Scheduling Information shall be triggered in case of CCCHtransmission in Cell FACH state:

-   -   In CELL_DCH state, when MAC-i is configured, and in CELL_FACH        state for FDD and for DCCH/DTCH transmission, if the size of the        data plus header is less than or equal to the TB size of the        E-TFC selected by the UE minus 18 bits, a Scheduling Information        shall be concatenated into this MAC-i PDU. Otherwise a        Scheduling Information is not included. [ . . . ]    -   For FDD and for DTCH/DCCH transmission in CELL_FACH state, the        transmission of Scheduling Information shall be triggered once,        if the TEBS remains zero and no higher layer data remains in MAC        to be transmitted for a period given by the E-DCH transmission        continuation back off period unequal “infinity”. For FDD and for        DTCH/DCCH transmission in CELL_FACH state with E-DCH        transmission continuation back off period set to “infinity” or        “zero”, the transmission of Scheduling Information shall be        triggered each lime when the TEBS becomes zero and no higher        layer data remains in MAC to be transmitted after the        transmission of the MAC-i PDU containing the scheduling        information with the empty buffer status report. When “E-DCH        transmission continuation back off” is set to “infinity”, the        Scheduling Information with empty buffer status report shall be        transmitted with the MAC-i PDU carrying the last DCCH/DTCH data,        given the serving grant is sufficient to carry the SI in the        same MAC-i PDU together with the remaining DCCH/DTCH data.        Otherwise, the Scheduling Information with empty buffer status        report is transmitted separately with the next MAC-i PDU.

The RNC communicates to the Node B the enabling of the implicit releaseusing an Information Element contained in the “Common E-DCH SystemInformation” (Ref [3] section 9.2.2.103):

>Common E-DCH M BOOLEAN TRUE means — implicit release implicit indicatorrelease is in use. FALSE means implicit release is not in use.

The Node B is not aware of the “E-DCH transmission continuation backoff” value.

If Implicit resource release is enabled, then the transmission of theScheduling Information with a TEBS value equal to zero will determinethe release of the common E-DCH resources by the UE. The indication ofTEBS=0 may be also used by the network in order to release the commonE-DCH resources assigned to that UE.

If implicit resource release is enabled, then in case of DTCH/DCCHtransmission, the timer Tb, also referred to as the inactivity timer orimplicit release timer, is set to “E-DCH transmission continuation backoff” value, when TEBS is 0 byte and the last generated MAC-i PDU withhigher layer data is provided with the PHY-data-REQ primitive to thephysical layer for transmission. That means that if the timer Tb is setto a value different from 0, the UE will not send the SI as soon asTEBS=0 is detected, but it will have to wait for the timer expiry. Atthe same time, if enough space is available at the end of a MAC-i PDUduring DCCH/DTCH transmission in CELL_FACH state, the UE attaches theScheduling Information. If during a DCCH/DTCH transmission in CELL_FACHthe TEBS value becomes 0, and there is enough space at the end of aMAC-i PDU, the UE will attach a Scheduling Information with TEBS=0indication, regardless of whether the Tb timer has expired.

From a UE perspective this does not represent an issue, as the releaseof the common E-DCH resources is not affected by the sending of this SIwith TEBS=0 (in order to release the resources the UE will have totrigger once more the SI with TEBS=0 when the timer Tb expires).

The Node B is not aware of whether the SI with TEBS=0 corresponds to animplicit release from the UE. This is due to the fact that the Node B isnot aware of the “E-DCH transmission continuation back off” value, hencecannot determine if the timer Tb has expired. Nor is the Node B aware ofwhether the SI is simply triggered because of enough space in the MAC-iPDU, but the timer Tb has not expired yet. This means that as soon asthe network gets the Scheduling Information (SI) with TEBS set to 0, thenetwork will understand that the UE is implicitly releasing theresources. However, this may not be the case. If the network uses the SIto release the resources when SI indicates TEBS set to 0, then the UEwill detect a radio link failure and data may be lost.

In a particular example embodiment, the proposed technology providesimproved support for implicit release using scheduling information fordedicated channel, e.g., DCCH/DTCH, transmission in CELL_FACH state andIdle mode. The Node B is made aware of whether the “E-DCH transmissioncontinuation back off” value is set to 0 or to a value different from 0.In this way, upon reception of a piggybacked SI with TEBS=0, the Node Bitself can determine whether that is due to an implicit release or not.A piggybacked SI is Scheduling Information that is sent together(concatenated) with data, e.g. in a MAC PDU, if there are enough sparebits at the end of the MAC PDU.

The following sets forth specific details, such as particularnon-limiting example embodiments for purposes of explanation and notlimitation. But it will be appreciated by one skilled in the art thatother embodiments may be employed apart from these specific details. Insome instances, detailed descriptions of well known methods, nodes,interfaces, circuits, and devices are omitted so as not obscure thedescription with unnecessary detail. Those skilled in the art willappreciate that the functions described may be implemented in one ormore nodes using hardware circuitry (e.g., analog and/or discrete logicgates interconnected to perform a specialized function, ApplicationSpecific Integrated Circuits, ASICs, Programmable Logic Arrays, PLAs,etc.) and/or using software programs and data in conjunction with one ormore digital microprocessors or general purpose computers. Nodes thatcommunicate using the air interface also have suitable radiocommunications circuitry. Moreover, the technology can additionally beconsidered to be embodied entirely within any form of computer-readablememory, such as solid-state memory, magnetic disk, or optical diskcontaining an appropriate set of computer instructions that would causea processor to carry out the techniques described herein.

Hardware implementation may include or encompass, without limitation,Digital Signal Processor, DSP, hardware, a reduced instruction setprocessor, hardware (e.g., digital or analog) circuitry including butnot limited to Application Specific Integrated Circuit(s), ASICs, and/orField Programmable Gate Array(s), FPGA(s), and (where appropriate) statemachines capable of performing such functions.

In terms of computer implementation, a computer is generally understoodto comprise one or more processors or one or more controllers, and theterms computer, processor, and controller may be employedinterchangeably. When provided by a computer, processor, or controller,the functions may be provided by a single dedicated computer orprocessor or controller, by a single shared computer or processor orcontroller, or by a plurality of individual computers or processors orcontrollers, some of which may be shared or distributed. Moreover, theterm “processor” or “controller” also refers to other hardware capableof performing such functions and/or executing software, such as theexample hardware recited above.

It should be understood by the skilled in the art that “UE” is anon-limiting term comprising any wireless device or node equipped with aradio interface allowing for at least one of: transmitting signals inUplink, UL, and receiving and/or measuring signals in Downlink, DL. A UEherein may comprise a UE (in its general sense) capable of operating orat least performing measurements in one or more frequencies, carrierfrequencies, component carriers or frequency bands. It may be a “UE”operating in single- or multi-RAT or multi-standard mode.

A cell is associated with a base station, where a base station comprisesin a general sense any node transmitting radio signals in the downlink,DL, and/or receiving radio signals in the uplink, UL. Some example basestations are eNodeB, eNB, Node B, macro/micro/pico radio base station,home eNodeB (also known as femto base station), relay, repeater, sensor,transmitting-only radio nodes or receiving-only radio nodes. A basestation may operate or at least perform measurements in one or morefrequencies, carrier frequencies or frequency bands and may be capableof carrier aggregation. It may also be a single Radio Access Technology,RAT, multi-RAT, or multi-standard node, e.g., using the same ordifferent base band modules for different RATs.

The signaling described is either via direct links or logical links(e.g. via higher layer protocols and/or via one or more network nodes).For example, signaling from a coordinating node may pass another networknode, e.g., a radio node.

The example embodiments are described in the non-limiting examplecontext of a UTRAN type system. However, the technology is not limitedto UTRAN, but may apply to any Radio Access Network, RAN, single-RAT ormulti-RAT. Some other RAT examples are Long Term Evolution Advanced,LTE-Advanced, Universal Mobile Telecommunications System, UMTS, GlobalSystem for Mobile communications, GSM, cdma2000, WiMAX, and WiFi. Ifapplying the technology to LTE, for example, those skilled in the artwill understand that the MAC entities in LTE have different names andfunctionalities.

In general, after an initial data transmission by a UE to a basestation, e.g., Node B, using common or shared radio resource(s) (e.g.,common E-DCH resources) allocated by the Node B, where the UE is in afirst connection state or mode in the Node B cell in which only commonradio resources are available to the UE, e.g., a CELL_FACH session, theUE maintains the common radio resource(s) until an inactivity timerexpires. During a CELL_FACH session, an inactivity timer is used fordetermining when the UE needs to release the allocated common resources.After the UE empties its transmit buffer, the inactivity timer starts,and once it reaches a predetermined timer expiration value, the UEreleases its allocated common resources. Thereafter, another datatransmission from the UE must start from the random access procedure.The inactivity timer, which is also referred to as a timer for implicitrelease of common resources or simply an implicit release timer, iscontrolled by the RNC and broadcasted to the relevant UE(s) in thesystem information.

FIG. 10 is a flowchart diagram illustrating example procedures inaccordance with one non-limiting embodiment. In step S21, the RNCsignals to the Node B the timer for implicit release. In step S22, thebase station (Node B), at some time, receives a piggybacked SI withTEBS=0. In step S23, it is determined in the base station whether thetimer for implicit release=0. If the timer for implicit release=0 (Y),the base station releases the common E-DCH resources in step S24. If thetimer for implicit release≠0 (N), the base station does not release thecommon E-DCH resources in step S25.

By way of example, a new information element (IE) or other type ofmessage or signal can be added to indicate the E-DCH transmissioncontinuation back off timer for implicit release, i.e. the implicitrelease timer. The value in an example embodiment is signaled from aControlling Radio Network Controller, CRNC, to a Node B. The CRNC is theRNC responsible for the configuration of the considered Node B.

In another example embodiment, the CRNC may add the new timer value inthe Node B Application Part, NBAP, control plan message. In the 3GPPUTRAN architecture, NBAP is the signaling protocol responsible forcontrol of the Node B by the RNC, and forms part of the Iub interface.

In another example embodiment, the CRNC may indicate whether the timeris zero or larger than zero.

In another example embodiment, the CRNC may indicate to the Node Bwhether Tb shall be set or not (if the continuation back-off timer is 0,then the UE does not set Tb).

In another example embodiment, the CRNC may indicate the exact value ofthe implicit timer to Node B.

For example, the new IE may be added into the Physical Shared ChannelReconfiguration procedure and into the message PHYSICAL SHARED CHANNELRECONFIGURATION REQUEST. When the Node B gets the implicit timer value,it applies the value for the Enhanced Cell FACH related configuration.In this way, the new implicit timer value is the same for the wholecell. Other examples can add the value in other NBAP messages, orintroduce the value in a new message.

Below is definition of the NBAP of TS 25.433 (rev 11.0.0) (chapter9.1.62.1), incorporated herein by reference, PHYSICAL SHARED CHANNELRECONFIGURATION REQUEST. The new IE can be added, for example, into IECommon E-DCH System Information.

IE Type and Semantics Criti- Assigned IE/Group Name Presence RangeReference Description cality Criticality Message Discriminator M9.2.1.45 — Message Type M 9.2.1.46 YES reject Transaction ID M 9.2.1.62— C-ID M 9.2.1.9 YES reject Configuration Generation ID M 9.2.1.16 YESreject SFN O 9.2.1.53A YES reject HS-PDSCH, HS-SCCH, E- O MaximumMaximum YES reject AGCH, E-RGCH and E-HICH Transmission transmissionTotal Power Power power to be 9.2.1.40 allowed for HS- PDSCH, HS- SCCH,E- AGCH, E- RGCH and E- HICH codes HS-PDSCH And HS-SCCH O DL ScramblingYES reject Scrambling Code Scrambling code on which Code HS-PDSCH9.2.2.13 and HS-SCCH is transmitted. 0 = Primary scrambling code of thecell 1 . . . 15 = Secondary scrambling code HS-PDSCH FDD Code O9.2.2.18F YES reject Information HS-SCCH FDD Code O 9.2.2.18G YES rejectInformation E-AGCH And E-RGCH/E- O DL Scrambling YES reject HICH FDDScrambling Code Scrambling code on which Code E-AGCH, E- 9.2.2.13 RGCHand E- HICH are transmitted. 0 = Primary scrambling code of the cell 1 .. . 15 = Secondary scrambling code E-AGCH Code FDD O 9.2.2.13Ib YESreject Information E-RGCH/E-HICH Code FDD O 9.2.2.13Ia YES rejectInformation HSDPA And E-DCH Cell 0 . . . <maxNoofCellPortions> GLOBALreject Portiors Information >Cell Portion ID M 9.2.2.1Ca — >HS-PDSCH AndHS- O DL Scrambling — SCCH Scrambling Code Scrambling code on which CodeHS-PDSCH 9.2.2.13 and HS-SCCH is transmitted over cellportion. >HS-PDSCH FDD Code O 9.2.2.18F — Information >HS-SCCH FDD CodeO 9.2.2.18G — Information >HS-PDSCH, HS-SCCH, E- O Maximum Maximum —AGCH, E-RGCH and E- Transmission transmission HICH Total Power Powerpower to be 9.2.1.40 allowed for HS- PDSCH, HS- SCCH and E- AGCH, E-RGCH and E- HICH codes over cell portion >E-AGCH And E-RGCH/E- O DLScrambling — HICH FDD Scrambling Scrambling code on which Code CodeE-AGCH, E- 9.2.2.13 RGCH and E- HICH are transmitted over cellportion. >E-AGCH Code FDD O 9.2.2.13Ib — Information >E-RGCH/E-HICH CodeO 9.2.2.13Ia — FDD Information >Maximum Target O 9.2.2.21a YES ignoreReceived Total Wide Band Power >Reference Received Total O 9.2.2.39B YESignore Wide Band Power Maximum Target Received O 9.2.2.21a YES rejectTotal Wide Band Power Reference Received Total O 9.2.2.39B YES ignoreWide Band Power Target Non-serving E-DCH to O 9.2.2.21b YES reject TotalE-DCH Power ratio HS-DSCH Common System O 9.2.2.75 YES rejectInformation Common MAC Flows to O 9.2.2.97 YES reject Delete HS-DSCHPaging System O 9.2.2.76 YES reject Information Paging MAC Flows toDelete O 9.2.2.98 YES reject Common E-DCH System O 9.2.2.103 YES RejectInformation Common UL MAC Flows to O Common YES Reject Delete MAC Flowsto Delete 9.2.2.97 Common E-DCH MAC-d O E-DCH YES Reject Flows to DeleteMAC Flows to Delete 9.2.1.73 Enhanced UE DRX O 9.2.2.108 YES rejectInformation

A new IE can be added to indicate the implicit release timer duringcommon E-DCH release. The value may be signaled from the CRNC to theNode B.

An alternative approach is to add the new timer value in the NBAPcontrol plan message. For example, if the new IE is added into thePhysical Shared Channel Reconfiguration procedure and into the messagePHYSICAL SHARED CHANNEL RECONFIGURATION REQUEST, then when the Node Bgets the implicit timer value, it should apply the value for theEnhanced Cell FACH related configuration. In this way, the new implicittimer value is the same for the whole cell. The IE in this example maybe defined with a criticality “ignore.”

Other examples may add the value in other NBAP messages or introduce thevalue in a new message.

Below shows the definition of chapter 9.2.2.103 Common E-DCH SystemInformation. The new IE “Common E-DCH Implicit Release Timer” in thisexample is added to indicate the implicit release timer. The CommonE-DCH System Information IE provides information for E-DCH configuredfor UE in Cell_FACH and Idle state.

IE Type and Semantics Criti- Assigned IE/Group Name Presence RangeReference Description cality Criticality Common E-DCH UL 0 . . . 1 —DPCH Information >UL SIR Target M UL SIR — 9.2.1.67A >DPC Mode O9.2.2.13C If received, this IE — shall be ignored. DPC mode 0 shall beapplied for Common E- DCH(see ref. TS 25.214 [10]). Common E-DCH E-DPCH0 . . . 1 — Information >Maximum Set of E- M 9.2.2.20C —DPDCHs >Puncture Limit M 9.2.1.50 — >E-TFCS Information M 9.2.2.13Dh— >E-TTI M 9.2.2.13Di — >E-DPCCH Power Offset M 9.2.2.13Dj — >E-RGCH2-Index-Step O 9.2.2.13Ig — Threshold >E-RGCH 3-Index-Step O 9.2.2.13Ih— Threshold >HARQ Info for E-DCH M 9.2.2.18ba — Common E-DCH 0 . . . 1 —Information >E-DCH Reference O 9.2.2.13Y — Power Offset >E-DCH PowerOffset for O 9.2.1.85 — Scheduling Info >Maximum E-DCH M ENUMERATEDInterms of TTIs, — resource allocation for (8, 12, 16, 24, Value 120should CCCH 32. 40, 80, not be used 120, . . . , 20) >Maximum period forM INTEGER Interms of TTIs — collision resolution phase (8 . . . 24, . ..) >Maximum TB Sizes O 9.2.2.106 — >Common E-DCH M BOOLEAN TRUE means —implicit release indicator implicit release is in use. FALSE meansimplicit release is not in use. >Common E-DCH O INTEGER YES ignoreAdditional Transmission (0 . . . 15, . . .) Back Off >Common E-DCH OCommon E-DCH YES ignore implicit release timer Implicit Release TimerCommon E-DCH HS- 0 . . . 1 — DPCCH Information >ACK-NACK Repetition M9.2.2.a — Factor >ACK Power Offset M 9.2.2.b — >NACK Power Offset M9.2.2.23a — >Common E-DCH CQI O — information >>CQI Feedback Cycle M9.2.2.21B — k >>CQI Repetition C- 9.2.2.4Cb — Factor CQICyclek >>CQIPower Offset M 9.2.2.4Ca — >>Measurement Power M 9.2.2.21C — OffsetCommon E-DCH 0 . . . 1 — Preamble Control Information >Common Physical M9.2.1.13 — Channel ID >Common E-DCH M Preamble — Preamble SignatureSignatures 9.2.2.31 >Scrambling Code M 9.2.2.42 — Number >PreambleThreshold M 9.2.2.32 — >E-AI Indicator O BOOLEAN TRUE means E-AIs — arein use on the AICH. FALSE means E-AIs are not in use on theAICH. >Common E-DCH AICH 0 . . . 1 — Information >>Common Physical M9.2.1.13 — Channel ID >>AICH Transmission M 9.2.2.1 — Timing >>FDD DL M9.2.2.14 — Channelisation Code Number >>AICH Power M 9.2.2.D — >>STTDIndicator M 9.2.2.48 — Common E-DCH F-DPCH 0 . . . 1 —Information >F-DPCH slot format M 9.2.2.93 — >FDD TPC DL Step Size M9.2.2.16 — >Initial DL Transmission O DL Power Initial power on YESignore Power 9.2.1.21 F-DPCH >Maximum DL Power O DL Power Maximum YESignore 9.2.1.21 allowed power on F-DPCH >Minimum DL Power O DL PowerMinimum allowed YES ignore 9.2.1.21 power on F- DPCH Common E-DCH E-AGCHO FDD DL — Channelisation Code Channelisation Number Code Number9.2.2.14 Common E-DCH 0 . . . <maxnoofCommonEDCHs> — ResourceCombination Information >Soffset M INTEGER — (0 . . . 9, . . .) >F-DPCHDL Code M FDD DL — Number Channelisation Code Number 9.2.2.14 >UL DPCHScrambling M UL Scrambling — Code Code 9.2.2.59 >E-RGCH/E-HICH M FDD DL— Channelisation Code Channelisation Code Number 9.2.2.14 >E-RGCHSignature O INTEGER — Sequence (0 . . . maxnoofSigSeqE- RGHICH− 1) >E-HICH Signature M INTEGER — Sequence (0 . . . maxnoofSigSeqE-RGHICH − 1) UL Common MAC Flow 0 . . . <maxnoofCommonMACFlows> —Specific Information >UL Common MAC Flow M Common MAC — ID Flow ID9.2.2.79 >Transport Bearer M 9.2.1.62A — Request Indicator >Binding ID O9.2.1.4 Shall be ignored if — bearer establishment withALCAP. >Transport Layer O 9.2.1.63 Shall be ignored if — Address bearerestablishment with ALCAP. >TNL QoS O 9.2.1.58A Shall be ignored if —bearer establishment with ALCAP. >Payload CRC Presence M 9.2.1.49 —Indicator >Bundling Mode Indicator O 9.2.2.1Bb — >Common E-DCH MAC- M9.2.2.105 — d Flow Specific Information E-RNTI List Request O NULL YESignore

The Common E-DCH Implicit Release Timer can be defined as INTEGER, or asENUMERATED values as show in the below examples:

IE Type and IE/Group Name Presence Range Reference Semantics DescriptionCommon E-DCH Implicit INTEGER (0 . . . 3600) Unit: ms Release TimerSemantics description Common E-DCH Implicit Enumerated (0, 4, 8, Interms of TTIs. Release Timer 16, 24, 40, 80) Common E-DCH ImplicitEnumerated (0, 4, 8, In terms of TTIs. Release Timer 16, 24, 40, 80,When set to “infinity”, implicit infinity) common E-DCH resource releaseis disabled. Common E-DCH Implicit ENUMERATED Release Timer (Zero, Morethan Zero, . . . )

Another alternative way is to add the new timer value in the Iub Frameprotocol so that CRNC can send the timer to Node B.

One example is to add a new IE in HS-DSCH data frame, which is usedtogether with Enhanced Cell FACH. Another example is to add a new IE tothe control frame, for example in High Speed Downlink Shared Channel,HS-DSCH, Capacity Request. A new User Plane frame can also be introducedto carry the information.

FIG. 11 shows an example of a user equipment (UE) 14 that can be used inone or more of the non-limiting example embodiments described. The UE 14comprises a processing module 30 that controls the operation of the UE14. The processing module 30 is connected to a transceiver module 32with associated antenna(s) 34 which are used to receive and transmitsignals to/from a base station 4, 6 in the network 2. The user equipment14 also comprises a memory module 36 that is connected to the processingmodule 30 and that stores program and other information and datarequired for the operation of the UE 14. In some embodiments, the UE 14may optionally comprises a satellite positioning system (e.g. GPS)receiver module 38 that can be used to determine the position and speedof movement of the UE 14.

FIG. 12 shows an example of a base station 4, 6 (called a Node B inUMTS) that can be used in example embodiments described above. The basestation 4, 6 comprises a processing module 40 that controls theoperation of the base station 4, 6. The processing module 40 isconnected to a transceiver module 42 with associated antenna(s) 44 whichare used to transmit signals to, and receive signals from, userequipments 14 in the network 2. The base station 4, 6 also comprises amemory module 46 that is connected to the processing module 40 and thatstores program and other information and data required for the operationof the base station 4, 6. The base station 4, 6 also includes componentsand/or circuitry 48, called a RNC interface in FIG. 12, for allowing thebase station 4, 6 to exchange information with the RNC 8 (which istypically via the Iub interface) and/or other network node.

FIG. 13 shows an example of a radio network controller (RNC) 8 that canbe used in the example embodiments described. The RNC 8 comprises aprocessing module 50 that controls the operation of the RNC 8. Theprocessing module 50 is connected to components and/or circuitry 52 forallowing the RNC 8 to exchange information with the base stations 4, 6with which it is associated (which is typically via the Iub interface),and components or circuitry 54 for allowing the RNC 8 to exchangeinformation with the core network 10 (which is typically via the Iu-CSand/or Iu-PS interface). The RNC 8 also comprises a memory module 56that is connected to the processing module 50 and that stores programand other information and data required for the operation of the RNC 8.

It will be appreciated that not all components of the UE 14, basestation B 4, 6, and RNC 8 are illustrated.

The above technology includes multiple advantages. For example, the NodeB may release common E-DCH resources to the network as soon as itinterprets the piggybacked SI with TEBS=0 as an implicit release. Incase of network implementations not aware of this issue, there is norisk that the network would release the common E-DCH resources when theUE sends a piggybacked SI with TEBS=0 before the timer Tb has expired,i.e., without having triggered the implicit release procedure.

According to a further particular aspect of the proposed technology,there is provided a method and corresponding base station configured forsupporting release of common Enhanced Dedicated Channel, E-DCH,resources in a radio communication network. As illustrated in FIG. 4,the base station is receiving in step S1′ a PHYSICAL SHARED CHANNELRECONFIGURATION REQUEST message from a radio network controllerincluding a ‘Common E-DCH Implicit Release Timer’ information element,IE, that indicates whether a ‘E-DCH transmission continuation back off’period is set to zero or to a value different from zero. For example,the ‘Common E-DCH Implicit Release Timer’ IE is included in a “CommonE-DCH Information” IE in a ‘Common E-DCH System Information’ IE.Reference can also be made to FIGS. 8, 9 and 12.

According to yet another particular aspect of the proposed technology,there is also provided a method and corresponding radio networkcontroller configured for supporting release of common EnhancedDedicated Channel, E-DCH, resources in a radio communication network. Asillustrated in FIG. 7, the radio network controller is sending in stepS11′ a PHYSICAL SHARED CHANNEL RECONFIGURATION REQUEST message to a basestation including a ‘Common E-DCH Implicit Release Timer’ informationelement to indicate whether a ‘E-DCH transmission continuation back off’period is set to zero or to a value different from zero. For example,the ‘Common E-DCH Implicit Release Timer’ IE is included in a “CommonE-DCH Information” IE in a ‘Common E-DCH System Information’ IE.Reference can also be made to FIGS. 8, 9 and 13.

The present technology is applicable to all relevant releases of theapplicable standards, including at least the 3GPP TS 25.433 standardRelease 8 to Release 11 and onwards.

ABBREVIATIONS

-   -   3GPP 3^(rd) Generation Partnership Project    -   CCCH Common Control Channel    -   BS Base Station    -   CN Core Network    -   DCCH Dedicated Control Channel    -   DCH Dedicated Channel    -   DTCH Dedicated Traffic Channel    -   E-DCH Enhanced Dedicated Channel    -   E-AGCH E-DCH Absolute Grant Channel    -   FACH Forward Access Channel    -   HARQ Hybrid Automatic Repeat Request    -   HSPA High Speed Packet Access    -   L1 Layer 1 (physical layer)    -   MAC Medium Access Control Protocol    -   AM Acknowledged Mode    -   PDU Protocol Data Unit    -   RACH Random Access Channel    -   RLC Radio Link Control    -   RNC Radio Network Controller    -   RRC Radio Resource Control Protocol    -   SDU Service Data Unit    -   SI Scheduling Information    -   SIB System Information Block    -   TEBS Total E-DCH Buffer Status    -   UE User Equipment    -   FDD Frequency Division Duplexing    -   TTI Time Transmission Interval    -   UMTS Universal Mobile Telecommunications System    -   UTRA UMTS Terrestrial Radio Access    -   UTRAN UMTS Terrestrial Radio Access Network

References incorporated by reference (relevant parts referred to in thepresent specification):

-   [1] 3GPP TS 25.321 v8.15.0, “Medium Access Control (MAC) protocol    specification”-   [2] 3GPP TS 25.331 v8.19.0. “Radio Resource Control (RRC); Protocol    specification”-   [3] 3GPP TS 25.433 v8.12.0 “UTRAN Iub interface Node B Application    Part (NBAP) signalling”

Although the description above contains many specifics, they should notbe construed as limiting but as merely providing illustrations of somepresently preferred embodiments. Embodiments described herein may beconsidered as independent embodiments or may be considered in anycombination with each other to describe non-limiting examples. Althoughnon-limiting, example embodiments of the technology were described in aUTRAN context, the principles of the technology described may also beapplied to other radio access technologies.

Indeed, the technology fully encompasses other embodiments which maybecome apparent to those skilled in the art. Reference to an element inthe singular is not intended to mean “one and only one” unlessexplicitly so stated, but rather “one or more.” All structural andfunctional equivalents to the elements of the above-describedembodiments that are known to those of ordinary skill in the art areexpressly incorporated herein by reference and are intended to beencompassed hereby. Moreover, it is not necessary for a device or methodto address each and every problem sought to be solved by the describedtechnology for it to be encompassed hereby.

What is claimed is:
 1. A method performed by a base station forsupporting release of common radio resources in a radio communicationnetwork, said method comprising the steps of: receiving an indication ofa value of a timer for implicit release of common radio resources from aradio network controller; and determining whether to release the commonradio resources based on said indication of the value of said timer forimplicit release of common radio resources.
 2. The method of claim 1,wherein said common radio resources are common Enhanced DedicatedChannel (E-DCH) resources, and said indication is an indication of avalue of a timer for implicit release of common E-DCH resources.
 3. Themethod of claim 2, wherein said indication of the value of said timerfor implicit release of common E-DCH resources indicates whether an“E-DCH transmission continuation back off” period is set to zero or to avalue different from zero.
 4. The method of claim 2, wherein said stepdetermining whether to release the common radio resources is performedupon reception of a report of empty buffer status from a User Equipment(UE).
 5. The method of claim 3, wherein said report of empty bufferstatus is received as piggybacked Scheduling Information (SI) with aTotal E-DCH Buffer Status (TEBS) value equal to zero.
 6. The method ofclaim 5, wherein said step of determining whether to release said commonradio resources includes the step of determining, based on saidindication of the value of said timer for implicit release of commonE-DCH resources, whether said report of empty buffer status from the UEis due to an implicit release of the common E-DCH resources by the UE.7. The method of claim 5, further comprising the step of said basestation releasing the common E-DCH resources if said indication of thevalue of said timer for implicit release of common E-DCH resources isequal to zero.
 8. The method of claim 5, further comprising the step ofsaid base station not releasing the common E-DCH resources if saidindication of the value of said timer for implicit release of commonE-DCH resources is different from zero.
 9. The method of claim 1,wherein said indication is received in a PHYSICAL SHARED CHANNELRECONFIGURATION REQUEST message.
 10. The method of claim 9, wherein saidindication is included in a “Common E-DCH Implicit Release Timer”information element (IE) in said PHYSICAL SHARED CHANNEL RECONFIGURATIONREQUEST message.
 11. The method of claim 10, wherein said indication inthe “Common E-DCH Implicit Release Timer” IE is defined to be ofENUMERATED type with values zero or more than zero.
 12. A methodperformed by a radio network controller for supporting release of commonradio resources in a radio communication network, said method comprisingthe step of: said radio network controller sending an indication of avalue of a timer for implicit release of common radio resources to abase station, to thereby enable the base station to determine whether torelease the common radio resources based on said indication.
 13. Themethod of claim 12, wherein said common radio resources are commonEnhanced Dedicated Channel (E-DCH) resources, and said indication is anindication of a value of a timer for implicit release of common E-DCHresources.
 14. The method of claim 13, wherein said indication of thevalue of said timer for implicit release of common E-DCH resourcesindicates whether a “E-DCH transmission continuation back off” period isset to zero or to a value different from zero.
 15. The method of claim13, wherein said radio network controller sends said indication of thevalue of said timer for implicit release of common E-DCH resources tothe base station to enable the base station to determine, based on saidindication, whether to release the common E-DCH resources upon receptionof a report of empty buffer status from a User Equipment (UE).
 16. Themethod of claim 15, wherein said radio network controller sends saidindication of the value of said timer for implicit release of commonE-DCH resources to the base station to enable the base station todetermine, based on said indication, whether to release the common E-DCHresources upon reception of piggybacked Scheduling Information (SI) witha Total E-DCH Buffer Status (TEBS) value equal to zero from the UE. 17.The method of claim 16, wherein said radio network controller sends saidindication of the value of said timer for implicit release of commonE-DCH resources to the base station to enable the base station torelease, upon reception of said report of empty buffer status from saidUE, said common E-DCH resources if said indication of the value of saidtimer for implicit release of common E-DCH resources is equal to zeroand to not release said common E-DCH resources if said indication of thevalue of said timer for implicit release of common E-DCH resources isdifferent from zero.
 18. The method of claim 12, wherein said methodcomprises the step of said radio network controller adding aninformation element (IE) including said indication to a message, andwherein said step of said radio network controller sending saidindication comprises the step of said radio network controller sendingsaid message with said added IE to said base station.
 19. The method ofclaim 12, wherein said radio network controller sends said indication tothe base station in a PHYSICAL SHARED CHANNEL RECONFIGURATION REQUESTmessage.
 20. The method of claim 19, wherein said indication is includedin a “Common E-DCH Implicit Release Timer” information element (IE) insaid PHYSICAL SHARED CHANNEL RECONFIGURATION REQUEST message.
 21. Themethod of claim 20, wherein said indication in the “Common E-DCHImplicit Release Timer” IE is defined to be of ENUMERATED type withvalues zero or more than zero.
 22. A base station for a radiocommunication network, wherein said base station comprises: an interfaceconfigured to receive an indication of a value of a timer for implicitrelease of common radio resources from a radio network controller; and aprocessing module configured to determine whether to release commonradio resources based on said indication.
 23. The radio base station ofclaim 22, wherein said indication indicates a value of a timer forimplicit release of common Enhanced Dedicated Channel (E-DCH) resources,and said processing module is configured to determine whether to releasecommon E-DCH resources responsive to the indication.
 24. The basestation of claim 23, wherein said interface is configured to receivesaid indication in the form of an indication of whether a value of a“E-DCH transmission continuation back off” period is set to zero or to avalue different from zero.
 25. The base station of claim 23, whereinsaid processing module is configured to determine, based on saidindication, whether to release said common radio resources uponreception of a report of empty buffer status from a User Equipment (UE).26. The base station of claim 25, wherein said base station comprises atransceiver module configured to receive said report of empty bufferstatus as piggybacked Scheduling Information (SI) with a Total E-DCHBuffer Status (TEBS) value equal to zero.
 27. The base station of claim26, wherein said processing module is configured to release said commonE-DCH resources if said indication of the value of said timer forimplicit release of common E-DCH resources is equal to zero.
 28. Thebase station of claim 26, wherein said processing module is configuredto maintain said common E-DCH resources if said indication of the valueof said timer for implicit release of common E-DCH resources isdifferent from zero.
 29. The base station of claim 23, wherein saidinterface is configured to receive said indication in a “Common E-DCHImplicit Release Timer” information element (IE) in a PHYSICAL SHAREDCHANNEL RECONFIGURATION REQUEST message.
 30. A radio network controllerfor a radio communication network, wherein said radio network controllercomprises an interface configured to send an indication of a value of atimer for implicit release of common radio resources to a base station,to thereby enable the base station to determine whether to releasecommon radio resources based on said indication.
 31. The radio networkcontroller of claim 30, wherein said interface is configured to send assaid indication an indication of a value of a timer for implicit releaseof common Enhanced Dedicated Channel (E DCH) resources, to enable thebase station to determine whether to release common E-DCH resources. 32.The radio network controller of claim 31, wherein said interface isconfigured to send said indication in the form of an indication ofwhether a value of a “E-DCH transmission continuation back off” periodis set to zero or to a value different from zero.
 33. The radio networkcontroller of claim 30, wherein said radio network controller comprisesa processing module configured to add an information element (IE)including said indication in a message, and wherein said interface isconfigured to send said message to the base station.
 34. The radionetwork controller of claim 30, wherein said radio network controllercomprises a processing module configured to include said indication in a“Common E-DCH Implicit Release Timer” information element (IE) in aPHYSICAL SHARED CHANNEL RECONFIGURATION REQUEST message, and saidinterface is configured to send said PHYSICAL SHARED CHANNELRECONFIGURATION REQUEST message to the base station.